The Date field and its parent element both get required attributes when conditionally required

Problem/Motivation

When configuring a data form element to be conditionally required, its parent element becomes required too. This is an issue because the parent element is a div tag by default, and div tags should not have required attributes.

Steps to reproduce

- Create a webform
- Add a select field with 2 options A and B
- Add a date field and configure it to be required only if option B is selected.
- Notice how by default both the date field and its parent element get a "data-drupal-states" attribute with encoded JSON.
- After selecting option B from select field, notice how both the date field and its parent element get the "required" attribute enabled.

You can also import the YAML content below to reproduce this issue.

option:
  '#type': select
  '#title': Options
  '#options':
    A: A
    B: B
date:
  '#type': date
  '#title': Date
  '#states':
    required:
      ':input[name="option"]':
        value: B

Proposed resolution

Remove the line in \Drupal\webform\Plugin\WebformElement\DateBase::prepare() that adds the "data-drupal-states" attribute to the date field parent element. I suspect this was needed in the past, before the HTML date field existed.

Remaining tasks

- Create MR

User interface changes

N/A

API changes

N/A

Data model changes

N/A